Well, more than anything I wanted to present an alternative viewpoint. The author presented his as if it's the only way.
I arrived at my understanding after years of learning about photography and experience of doing it not professionally, taking tends of thousands of photos of all sorts of subjects. I think the point about emotional distance is under-appreciated.
Of course, this author (and I don't know why) clearly wanted to create the distance--you can see it by frequent use of monochrome/sepia coloring that mimics the nostalgic look of old photos. However, this was left unsaid, and someone may miss this factor when choosing the lens based on this article.
> Framing is not a problem that goes away if you use wide-angle lens. ... It's easier to get something in-frame, but harder to keep something out.
The core task is different IMO. When you are enjoying family time, especially with children, it's more important to 1) get something in frame in any way possible fast while 2) still being in the moment yourself than with other types of photography. If you are shooting children as models that's different, sure.
> I'm also not sure why it would take me longer to frame or focus with a 50mm lens. For candids, I almost always use an autofocus camera these days. It focuses at the touch of a button.
If you haven't tried wide-all-the-time, try. I shot a lot wide (20-28mm), 40-50mm and 75mm. With wider lenses I often shot from the hip with subsecond time between the moment and the shot, and got interesting dynamic frames (and I rarely crop). It just doesn't happen already at ~40mm, even if I spam shoot, I need to see the frame.
As to focus, you don't even need to focus many ~25mm lenses if you shoot with moderately closed aperture (just leave it around 5m~infinity). A longer lens makes it much easier for subject to be off, I have to make sure focus is right and a compact camera's autofocus is rarely reliable enough in low light to capture action. Remember that this is candid family shots, there's no proper lighting.
And 75mm, while great for street portraits or casual fashion, is additionally unusable as a main driver for candid family shots since in a random room you often can't back far enough away to capture enough of the action. In the circumstances described it's easier to come closer rather than opposite.
I thought 40-50mm would be a nice middle ground, but it doesn't give the really pronounced separation, bokeh and aesthetics of longer lenses like 75mm yet it does make things more challenging in all regards for no good (to me) reason. I find it OK for street shots but now I am more informed about its limitations in other scenarios.